/**
* (c) Copyright 2014 WibiData, Inc.
*
* See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.kiji.schema.layout.impl.hbase;
import com.google.common.base.Objects;
import org.apache.commons.lang.ArrayUtils;
import org.apache.hadoop.hbase.util.Bytes;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.kiji.annotations.ApiAudience;
import org.kiji.schema.KijiColumnName;
import org.kiji.schema.NoSuchColumnException;
import org.kiji.schema.hbase.HBaseColumnName;
import org.kiji.schema.layout.HBaseColumnNameTranslator;
import org.kiji.schema.layout.KijiTableLayout;
import org.kiji.schema.layout.KijiTableLayout.LocalityGroupLayout;
import org.kiji.schema.layout.KijiTableLayout.LocalityGroupLayout.FamilyLayout;
import org.kiji.schema.layout.KijiTableLayout.LocalityGroupLayout.FamilyLayout.ColumnLayout;
import org.kiji.schema.layout.impl.ColumnId;
/**
* Translates between HBase and Kiji column names.
*
* <p>This class defines a mapping between names of HBase families/qualifiers and
* Kiji locality group/family/qualifiers using a custom base-64 encoding based on the ids of each
* individual column.</p>
*/
@ApiAudience.Private
public final class ShortColumnNameTranslator extends HBaseColumnNameTranslator {
private static final Logger LOG = LoggerFactory.getLogger(ShortColumnNameTranslator.class);
/** Used to separate the Kiji family from the Kiji qualifier in an HBase qualifier. */
private static final byte SEPARATOR = ':';
/** The table to translate names for. */
private final KijiTableLayout mLayout;
/**
* Creates a new {@link ShortColumnNameTranslator} instance.
*
* @param tableLayout The layout of the table to translate column names for.
*/
public ShortColumnNameTranslator(KijiTableLayout tableLayout) {
mLayout = tableLayout;
}
/** {@inheritDoc} */
@Override
public KijiColumnName toKijiColumnName(HBaseColumnName hbaseColumnName)
throws NoSuchColumnException {
LOG.debug("Translating HBase column name '{}' to Kiji column name...", hbaseColumnName);
final ColumnId localityGroupID = ColumnId.fromByteArray(hbaseColumnName.getFamily());
final LocalityGroupLayout localityGroup =
mLayout.getLocalityGroupMap().get(mLayout.getLocalityGroupIdNameMap().get(localityGroupID));
if (localityGroup == null) {
throw new NoSuchColumnException(String.format("No locality group with ID %s in table %s.",
localityGroupID.getId(), mLayout.getName()));
}
// Parse the HBase qualifier as a byte[] in order to save a String instantiation
final byte[] hbaseQualifier = hbaseColumnName.getQualifier();
final int index = ArrayUtils.indexOf(hbaseQualifier, SEPARATOR);
if (index == -1) {
throw new NoSuchColumnException(String.format(
"Missing separator in HBase column %s.", hbaseColumnName));
}
final ColumnId familyID = ColumnId.fromString(Bytes.toString(hbaseQualifier, 0, index));
final String rawQualifier =
Bytes.toString(hbaseQualifier, index + 1, hbaseQualifier.length - index - 1);
final FamilyLayout family =
localityGroup.getFamilyMap().get(localityGroup.getFamilyIdNameMap().get(familyID));
if (family == null) {
throw new NoSuchColumnException(String.format(
"No family with ID %s in locality group %s of table %s.",
familyID.getId(), localityGroup.getName(), mLayout.getName()));
}
if (family.isGroupType()) {
// Group type family.
final ColumnId qualifierID = ColumnId.fromString(rawQualifier);
final ColumnLayout qualifier =
family.getColumnMap().get(family.getColumnIdNameMap().get(qualifierID));
if (qualifier == null) {
throw new NoSuchColumnException(String.format(
"No column with ID %s in family %s of table %s.",
qualifierID.getId(), family.getName(), mLayout.getName()));
}
final KijiColumnName kijiColumnName =
new KijiColumnName(family.getName(), qualifier.getName());
LOG.debug("Translated to Kiji group column {}.", kijiColumnName);
return kijiColumnName;
} else {
// Map type family.
assert family.isMapType();
final KijiColumnName kijiColumnName = new KijiColumnName(family.getName(), rawQualifier);
LOG.debug("Translated to Kiji map column '{}'.", kijiColumnName);
return kijiColumnName;
}
}
/** {@inheritDoc} */
@Override
public HBaseColumnName toHBaseColumnName(final KijiColumnName kijiColumnName)
throws NoSuchColumnException {
final String familyName = kijiColumnName.getFamily();
final String qualifierName = kijiColumnName.getQualifier();
final FamilyLayout family = mLayout.getFamilyMap().get(familyName);
if (family == null) {
throw new NoSuchColumnException(kijiColumnName.toString());
}
final ColumnId localityGroupID = family.getLocalityGroup().getId();
final ColumnId familyID = family.getId();
final byte[] localityGroupBytes = Bytes.toBytes(localityGroupID.toString());
final byte[] familyBytes = Bytes.toBytes(familyID.toString());
if (qualifierName == null) {
// Unqualified column
return new HBaseColumnName(localityGroupBytes,
concatWithSeparator(SEPARATOR, familyBytes, new byte[]{}));
} else if (family.isGroupType()) {
// Group type family.
final ColumnId qualifierID = family.getColumnIdNameMap().inverse().get(qualifierName);
final byte[] qualifierBytes = Bytes.toBytes(qualifierID.toString());
return new HBaseColumnName(localityGroupBytes,
concatWithSeparator(SEPARATOR, familyBytes, qualifierBytes));
} else {
// Map type family.
assert family.isMapType();
final byte[] qualifierBytes = Bytes.toBytes(qualifierName);
return new HBaseColumnName(
localityGroupBytes,
concatWithSeparator(SEPARATOR, familyBytes, qualifierBytes));
}
}
/** {@inheritDoc} */
@Override
public byte[] toHBaseFamilyName(LocalityGroupLayout localityGroup) {
return Bytes.toBytes(localityGroup.getId().toString());
}
/** {@inheritDoc} */
@Override
public KijiTableLayout getTableLayout() {
return mLayout;
}
/**
* Append the byte arrays with a single byte separator.
*
* @param separator to insert between the two arrays.
* @param a first byte array.
* @param b second byte array.
* @return a concatenated with b with a separator byte in between.
*/
static byte[] concatWithSeparator(byte separator, byte[] a, byte[] b) {
final byte[] ret = new byte[a.length + b.length + 1];
System.arraycopy(
a, 0, // src, src position
ret, 0, // dst, dst position
a.length); // length
ret[a.length] = separator;
System.arraycopy(
b, 0, // src, src position
ret, a.length + 1, // dst, dst position
b.length); // length
return ret;
}
/** {@inheritDoc} */
@Override
public String toString() {
return Objects.toStringHelper(this)
.add("table", mLayout.getName())
.add("layout", mLayout)
.toString();
}
}